<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>下拉菜单</title>
</head>

<body>
  城市：
  <select>
    <option value="">北京</option>
    <option value="">上海</option>
    <option value="">深圳</option>
    <option value="" selected>武汉</option>
  </select>
</body>

</html>